Material submitted by a British Columbia ostrich farm to support another stay of an avian flu cull order for its flock is improper because it asks the court to decide on a matter of science, the Canadian Food Inspection Agency says.

The lawyer for Universal Ostrich Farms in Edgewood, B.C., had written to the Federal Court of Appeal on Wednesday seeking "retroactive" permission for having submitted the documents four hours late.

In response, the CFIA said Thursday that it has no objections to the extension, but that doesn't mean it agrees the submissions are "admissible or material" to the request for another stay.

An agency lawyer argues in a letter dated Thursday that a new expert report for the farm by a University of British Columbia professor covers "opinions" the court has already rejected.

"(The) new expert report largely repeats opinions contained in previous expert reports which the Federal Court has already found improperly ask the court to become 'an arbiter of truth in immunology and animal and public health,'" the letter said, quoting the court's May ruling.

Farm spokeswoman Katie Pasitney meanwhile said in a news release issued late Thursday that the farm has "formally petitioned" the minister of agriculture to rescind the cull order.

The farm is fighting a cull of about 400 birds that was ordered by the CFIA on Dec. 31, over an avian flu outbreak that went on to kill 69 birds.

The CFIA says there are ongoing risks posed by the flock and the conditions in which they are kept, while the farmers say the birds are healthy and scientifically valuable, having acquired "herd immunity."

The farm's situation has drawn attention from opponents of government overreach and the U.S. administration of President Donald Trump, whose Health Secretary, Robert F. Kennedy Jr., has called for the birds to be spared and studied.

Supporters of the farm have been camping out at the property, staging music concerts and other events to draw attention to the case.

The farm has already lost hearings in Federal Court and the Federal Court of Appeal and now says it wants another stay to prepare an application for the Supreme Court of Canada to hear its case.